HANDBOOK OF PHYSIOLOGY. 



nerve-fibres, from the ultimate ramifications of the cutaneous plexus, 

 on which their exquisite sensibility depends. 



The nerve-terminations in the skin have been described under the 

 Sensory Nerve Terminations (p. 102 et seq.). 



Glands of the Skin. The skin possesses glands of two kinds: (a) 

 Sudoriferous, or Sweat Glands; (b) Sebaceous glands. 



(a) Sudoriferous, or Sweat Glands. Each of these glands consists 

 of a small lobular mass, formed of a coil of tubular gland-duct, sur- 



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Fig. 311. Vertical section of skin. A. Sebaceous gland opening into hair follicle. B. Muscular 

 fibres. C. Sudoriferous or sweat-gland. D. Subcutaneous fat. E. Fundus of hair-follicle, with 

 hair-papillae. (Klein.) 



rounded by blood-vessels and embedded in the subcutaneous adipose 

 tissue (fig. 311, C). From this mass, the duct ascends, for a short dis- 

 tance in a spiral manner through the deeper part of the cutis, then 

 passing straight, and then sometimes again becoming spiral, it passes 

 through the epidermis and opens by an oblique valve-like aperture. 

 In the parts where the epidermis is thin, the ducts themselves are 

 thinner and more nearly straight in their course (fig. 311). The duct, 

 which maintains nearly the same diameter throughout, is lined with a 



